Construction of a Cascade Catalyst of Nanocoupled Living Red Blood Cells for Implantable Biofuel Cell.

The broad applications of implantable glucose biofuel cells (GBFCs) have become very attractive in biomedical sciences. The key challenge of GBFCs is eliminating the inevitable product H2O2 generated from the oxidation of glucose when glucose oxidase (GOx) is used as a catalyst while improving the performance of GBFCs. In this work, the cascade electrocatalyst, RBCs@NPDA was obtained through the in situ polymerization of dopamine to form nanopolydopamine (NPDA) on the surface of red blood cells (RBCs). The RBCs@NPDA can catalyze both fuels of H2O2 and O2, so as to generate a high cathodic current (0.414 mA cm-2). Furthermore, when RBCs@NPDA was used as a cathodic catalyst in the membraneless GBFC, it exhibited the cascade catalytic activity in the reduction of O2-H2O2 and minimized the damage to RBCs caused by the high concentration of H2O2. The mechanism research indicates that RBCs@NPDA integrates the property of NPDA and RBCs. Specifically, NPDA plays a catalase-like role in catalyzing the decomposition of H2O2, while RBCs play a laccase-like role in electrocatalyzing the O2 reduction reaction. This work offers the cascade catalyst for improving the performance of implantable GBFC and presents a strategy for constructing catalysts using living cells and nanomaterials to replace deformable and unstable enzymes in other biofuel cells.

Construction of bifunctional living red blood cells for combined photothermal-chemotherapy.

Modifying living cells using in-situ synthesized nanomaterials to endow them with new functions is highly desirable. Herein we report intra- and extra-cellular dual-modified red blood cells (RBCs) with intracellular CaCO3 nanoparticles (NPs) and extracellular polypyrrole-folic acid (PPy-FA) coating, which are exploited as a bifunctional drug carrier. The functionalized living cells (CaCO3@RBC@PPy-FA) are fabricated through first the intracellular in situ reaction of exogenous Ca2+ and CO32- ions to generate CaCO3 NPs, then polymerization of pyrrole and finally modification of folic acid (FA) on the membrane of individual cells, forming a CaCO3@RBC@PPy-FA structure. As a result, such dual-modified RBCs not only preserve the original performances of the cells but also possess the desirable properties as a drug carrier, such as high loading capacity due to the action of CaCO3 NPs, targeting and light-controlled drug release due to the action of PPy-FA. Under NIR laser stimulation, these bifunctional RBCs (DOX-CaCO3@RBC@PPy-FA) present an instant release profile of doxorubicin (DOX) and have high targeting-ability toward cancer cells, achieving a marked synergistic combined photothermal-chemotherapy effect.

Synergistic activation of persulfate by natural chalcocite and ferrous ions by promoting the cycling of Fe3+/Fe2+ couple for degradation of organic pollutants.

Natural chalcocite (NCC) was chosen as a co-catalyst for activation of persulfate (PS) to degrade organic contaminants in this study. A synergistic effect between NCC and ferrous ions (Fe2+) was found in catalyzing PS for degradation of orange G (OG). The main role of NCC in the NCC/Fe2+/PS system was to facilitate Fe3+ reduction back to Fe2+ and thus improve the stoichiometric efficiency of PS. The results of scavenging experiments and electron paramagnetic resonance tests proved that both sulfate and hydroxyl radicals were the primary reactive oxidants in the NCC/Fe2+/PS system. Twelve potential intermediate products of OG were identified, and the degradation pathway was proposed. Experiment parameters, such as NCC dose, Fe2+ concentration, initial pH, and the presence of anions (H2PO4‒ and Cl‒), all had important impacts on OG degradation. NCC had good reusability in synergistic activation of PS with Fe2+ for OG degradation for five cycles. This study demonstrated a natural sulfide mineral as an efficient co-catalyst towards PS activation for destruction of organic contaminants in water.

Occurrence and distribution of priority pharmaceuticals in the Yellow River and the Huai River in Henan, China.

The occurrence and spatial distribution of priority pharmaceuticals (PPs) in water samples from the Yellow River and the Huai River in the Henan region of China were investigated in this study. The concentration of the total PPs (ΣPPs; sum of the 10 observed PPs) ranged from not detected to 3474 ng L-1 in samples from the Yellow River and from 4.35 to 146 ng L-1 in samples from the Huai River. The level of the ΣPPs in the Huai River was much lower than that found in the Yellow River. The composition of the PPs differed between the two rivers. Norfloxacin, carbamazepine, and 5,5-diphenylhydantoin were detected at high concentrations in the Yellow River, whereas sulfamethazine, ampicillin trihydrate, carbamazepine, and 5,5-diphenylhydantoin were the dominant species in the Huai River, suggesting there were different pollution sources. In comparison to other studies around China, most of the PPs in water samples from the Yellow River and the Huai River were at low concentrations, except for norfloxacin and ofloxacin. There were significant seasonal variations among the PPs in water samples from the Huai River, whereas spatial distinctions were recorded among the PPs in the Yellow River. Dissolved organic carbon content did not correlate with the PPs in the studied area.